Phosphoglucose isomerase is involved in the early steps of glycolysis and regeneration of glucose‐6‐ phosphate pools in the pentose phosphate pathway (PPP). In Arabidopsis, the plastidial isoform of phosphoglucose isomerase, PGI1, is an important determinant of growth, metabolism and photosynthesis, probably due to its involvement in the synthesis of 2‐C‐methyl‐D‐erythritol 4‐P (MEP)‐ derived cytokinins (CK) in root tips and vascular tissues (Bahaji et al., 2015; Bahaji et al., 2018, Gámez‐ Arcas et al. 2022). To test this hypothesis, we conducted proteomic and metabolic characterization of PGI1‐null pgi1‐2 plants. We also characterized pgi1‐2 plants ectopically expressing PGI1 under the control of a root tip‐ and vascular tissue‐specific promoter. Compared with wild‐type (WT) leaves, pgi1‐2 leaves exhibited weaker expression of MEP pathway‐ and photosynthesis‐related proteins. Vascular‐ and root tip‐specific PGI1 expression reverted to WT the pgi1‐2 growth and metabolic phenotypes. Data obtained in this work provide strong evidence that root tip and vascular PGI1‐mediated plastidial PPP determines growth and photosynthesis through MEP pathway‐derived CK action

This work was supported by the Ministerio de Ciencia e Innovación (MCIN) and Agencia Estatal de Investigación (AEI) / 10.13039/501100011033/ (grants BIO2016‐78747‐P, PID2019‐104685GB‐100) and the Ministry of Education, Youth and Sport of the Czech Republic (No. CZ.02.1.01/0.0/0.0/16_019/0000827) within the program Research, Development, and Education (OP RDE).

Trabajo presentado en el Iberian Plant Biology 2023 - XVIII Portuguese-Spanish Congress on Plant Biology and the XXV Meeting of the Spanish Society of Plant Biology, celebrado en Braga (Portugal), del 9 al 12 de julio de 2023